Systems, methods, and devices for treating a tissue site on a mammal having hair proximate the tissue site

ABSTRACT

Systems, methods, and devices are presented for treating a tissue site and managing hair proximate the tissue site. A composition is provided for inhibiting, removing, or weakening hair proximate the tissue site and for providing an improved fluid seal by a flexible film drape over the tissue site. In some example embodiments, a hair-modification agent is disposed at least proximate a peripheral edge of a treatment manifold between a drape and epidermis proximate a tissue site. The hair-modification agent can be configured to flow over imperfections on the epidermis and to form a fluid seal against the epidermis, and can further be configured to at least substantially weaken hair on the epidermis as the hair encounters the hair-modification agent.

RELATED APPLICATION

The present invention claims the benefit, under 35 USC § 119(e), of thefiling of U.S. Provisional Patent Application Ser. No. 61/669,395,entitled “SYSTEMS, METHODS, AND DEVICES FOR TREATING A TISSUE SITEHAVING HAIR PROXIMATE THE TISSUE SITE,” filed 9 Jul. 2012, which isincorporated herein by reference for all purposes.

TECHNICAL FIELD

The present invention relates generally to tissue treatment systems andmore particularly, but without limitation, to a dressing having ahair-modification agent to modify hair adjacent a tissue site.

BACKGROUND

Dressings are often used to treat a tissue site of a patient. A dressingmay include many elements that are selected to generally promote growthor healing of tissue. Typically, a dressing may be placed next to atissue site, such as an open wound, for example. The dressing may coverthe tissue site to prevent the tissue site from becoming undesirablydry, prevent contamination of the tissue site from foreign agents, suchas undesirable bacteria, and prevent further injury to the tissue site.To accomplish these tasks, dressings are often secured to tissueadjacent the tissue site with an adhesive.

Using adhesives to secure a dressing can keep the dressing in place overa tissue site and limit inadvertent removal of the dressing that maylead to contamination or re-injury of the tissue site. Unfortunately,the adhesive may also irritate the tissue adjacent the tissue site andcan cause pain to a patient when the dressing is removed. The pain maybe associated in part with removal of hair bonded to the adhesive.

Some dressings may be applied to the tissue site for extended periods.For example, a dressing used with reduced-pressure therapy can be leftin place for many days. Hair growth under the dressing during suchtherapy may cause leaks, as well as increased pain upon removal of thedressing.

SUMMARY

According to an illustrative, non-limiting embodiment, a dressing fortreating a tissue site is described. The dressing includes a gaskethaving a sealing agent and a hair-modification agent associated with thesealing agent. The hair-modification agent is configured to modify hairon epidermis proximate the tissue site.

According to another illustrative, non-limiting embodiment, a system fortreating a tissue site is described. The system includes a pad having aperipheral edge and a drape adapted to cover the pad to form a sealedspace containing the pad. The system also includes a hair-modificationagent adapted to be disposed proximate the peripheral edge of the pad.The hair-modification agent may be further adapted to be disposedadjacent at least a portion of an epidermis to modify hair on theepidermis proximate the tissue site.

According to another illustrative, non-limiting embodiment, a dressingfor treating a tissue site is described. The dressing includes atreatment pad having a peripheral edge and a drape adapted to cover thetreatment pad to form a sealed space containing the treatment pad. Thedressing may also include a hair-modification layer having ahair-modification agent disposed therein. The hair-modification layermay be adapted to be disposed at least proximate the peripheral edge ofthe treatment pad and to be disposed adjacent at least a portion of anepidermis proximate the tissue site to seal the drape to and modify hairon the epidermis.

According to another illustrative, non-limiting embodiment, a method fortreating a tissue site is described. The method disposes a manifoldhaving a peripheral edge adjacent the tissue site and disposes a gaskethaving a sealing agent and a hair-modification agent proximate theperipheral edge of the manifold and adjacent at least a portion of anepidermis. The method disposes a drape over the manifold and the gasketto form a sealed space containing the manifold.

Other objects and advantages of the illustrative embodiments will becomeapparent with reference to the drawings and detailed description thatfollow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram with a portion shown in cross section ofan illustrative embodiment of a system for treating a tissue site, whichhas hair proximate the tissue site;

FIG. 2 is a cross sectional view of an illustrative embodiment of acomposition for sealing and modifying hair on an epidermis;

FIG. 3 is a perspective cross-sectional view of a portion of a systemfor treating a tissue site, which has hair proximate the tissue site;

FIG. 4 is a cross sectional view of an illustrative embodiment of acomposition for sealing and modifying hair;

FIG. 5 is a cross sectional view of another illustrative embodiment of acomposition for sealing and modifying hair;

FIG. 6 is a cross sectional view of another illustrative embodiment of acomposition for sealing and modifying hair disposed proximate a flexiblefilm drape;

FIG. 7 is a cross sectional view of another illustrative embodiment of acomposition for sealing and modifying hair disposed proximate a flexiblefilm drape;

FIG. 8 is a cross sectional view of another illustrative embodiment of acomposition for sealing and modifying hair;

FIG. 9 is a cross sectional view of another illustrative embodiment of acomposition for sealing and modifying hair disposed proximate a flexiblefilm drape;

FIG. 10 is a cross sectional view of another illustrative embodiment ofa composition for sealing and modifying hair;

FIG. 11 is a cross sectional view of another illustrative embodiment ofa composition for sealing and modifying hair;

FIG. 12A is a cross sectional view of a portion of the composition forsealing and modifying hair of FIG. 11 showing an illustrative embodimentof a hair-modification agent encapsulated within an activatable shellthat is shown in the un-activated state; and

FIG. 12B is a cross sectional view of the portion of the composition forsealing and modifying hair of FIG. 12A showing the activatable shell inthe activated state.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following detailed description of the illustrative embodiments,reference is made to the accompanying drawings that form a part hereof.These embodiments are described in sufficient detail to enable thoseskilled in the art to practice the invention, and it is understood thatother embodiments may be utilized and that logical structural,mechanical, electrical, and chemical changes may be made withoutdeparting from the spirit or scope of the invention. To avoid detail notnecessary to enable those skilled in the art to practice the embodimentsdescribed herein, the description may omit certain information known tothose skilled in the art. The following detailed description is,therefore, not to be taken in a limiting sense, and the scope of theillustrative embodiments are defined only by the appended claims.

In treating a tissue site on a patient, a dressing may often be used tosecure the dressing to the tissue site. The dressing may be secured withan adhesive that bonds to the dressing and to tissue that may beadjacent the tissue site. In some cases, the adhesive may irritate thetissue adjacent the tissue site. In some cases, the adhesive may bond tohair on the tissue adjacent the tissue site. When the dressing isremoved, such as when the tissue site is healed or a new dressing isrequired, for example, the adhesive may pull hair out of the tissueadjacent the tissue site, causing the patient pain.

Dressings are commonly applied to tissues sites in conjunction withreduced-pressure therapy, which can augment and accelerate growth of newtissue. The applications of this phenomenon are numerous, but it hasproven particularly advantageous for treating wounds. Regardless of theetiology of a wound, whether trauma, surgery, or another cause, propercare of the wound is important to the outcome. Treatment of wounds withreduced pressure may be commonly referred to as “reduced-pressuretherapy,” but is also known by other names, including “negative-pressurewound therapy,” “negative-pressure therapy,” “vacuum therapy,” and“vacuum-assisted closure,” for example. Reduced-pressure therapy mayprovide a number of benefits, including migration of epithelial andsubcutaneous tissues, improved blood flow, and micro-deformation oftissue at a wound site. Together, these benefits can increasedevelopment of granulation tissue and reduce healing times.

In treating a tissue site on a patient (human or other animal) withreduced pressure, an adequate fluid seal is required. With at least somedressings using relatively low-flow reduced-pressure sources or insituations in which the dressing remains in place for an extendedduration, hair, fur, or hair-like coverings may cause an unacceptableleak rate or otherwise interfere with the therapeutic application ofreduced-pressure. Moreover, when removing a dressing after an extendedperiod, considerable pain may be caused to the patient if hair hasbecome adhered to the dressing.

As disclosed herein, systems, methods, and devices for treating a tissuesite can overcome these shortcomings and others. Exemplary embodimentsdescribed herein can substantially reduce or eliminate irritation andpain that may be associated with using or removing dressings. Exemplaryembodiments are also described that can substantially reduce oreliminate leaks caused by hair growth proximate the tissue site. In someembodiments, a hair management system is described that can inhibit,remove, weaken, or otherwise modify hair. In yet more particularembodiments, a hair-modification agent is disposed or adapted to bedisposed adjacent an epidermis to modify hair on the epidermis proximatea tissue site.

Referring now to the drawings and, more specifically to FIG. 1, anillustrative embodiment of a system 100 for applying reduced pressure toa tissue site 102 on a patient 104 is presented, where the patient 104has hair 105 proximate the tissue site 102, as shown in more detail inFIGS. 2 and 3. The system 100 may include a composition 103, which maybe formed as a ring, a gasket, or other flexible annular member. In someembodiments, the composition 103 may form a fluid seal. In someembodiments, the composition 103 may manage hair proximate the tissuesite 102. In some embodiments, the composition 103 may form a fluid sealand manage hair proximate the tissue site 102. The tissue site 102 maybe, for example, a wound 106. The wound 106 may include, withoutlimitation, any irregularity with a tissue, such as an open wound,surgical incision, or diseased tissue. The wound 106 is shown extendingthrough an epidermis 107, or generally skin, and a dermis 108 andreaching into a hypodermis, or a subcutaneous tissue 110. The system 100may be used to treat a tissue site, such as a wound of any depth, aswell as many different types of tissue sites including open wounds orintact tissue. The tissue site 102 may be the bodily tissue of anorganism, including bone tissue, adipose tissue, muscle tissue, dermaltissue, vascular tissue, connective tissue, cartilage, tendons,ligaments, or other tissue.

The system 100 generally includes a treatment pad such as a treatmentmanifold 112, a drape such as a flexible film drape 114, and areduced-pressure source such as a reduced-pressure subsystem 120. Thetreatment manifold 112 may be operable to distribute reduced pressure.The flexible film drape 114 may provide a fluid seal over the treatmentmanifold 112 and the tissue site 102. “Fluid seal,” or “seal,” mayinclude a seal adequate to maintain reduced pressure at a desired sitegiven the particular reduced-pressure source or subsystem involved. Thesystem 100 may include an attachment device 122 to help form a fluidseal between the flexible film drape 114 and the epidermis 107. Theflexible film drape 114 has a first side 116 and a second side 118.

The treatment manifold 112 may be positioned between the second side 118of the flexible film drape 114 and the tissue site 102. The treatmentmanifold 112 may have a peripheral edge 113 that is the most outboardportion of the treatment manifold 112. The treatment manifold 112 mayhave a first side 115 and a second side 117.

The term “manifold” as used herein generally refers to a substance orstructure that is provided to assist in applying reduced pressure to,delivering fluids to, or removing fluids from a tissue site, e.g., thetissue site 102. The treatment manifold 112 includes a plurality of flowchannels or pathways that distribute fluids provided to and removed fromthe tissue site 102 around the treatment manifold 112. In oneillustrative embodiment, the flow channels or pathways areinterconnected to improve distribution of fluids provided to or removedfrom the tissue site 102. The treatment manifold 112 may include one ormore of the following: a biocompatible material that is capable of beingplaced in contact with the tissue site 102 and distributing reducedpressure to the tissue site 102. The treatment manifold 112 may alsoinclude devices that have structural elements arranged to form flowchannels, such as, for example, cellular foam, open-cell foam, poroustissue collections, liquids, gels, and foams that include, or cure toinclude, flow channels. The treatment manifold 112 may further includeporous material, such as foam, gauze, felted mat, or any other materialsuited to a particular biological application; or porous foam thatincludes a plurality of interconnected cells or pores that act as flowchannels, e.g., a polyurethane, open-cell, reticulated foam such asGranuFoam® material manufactured by Kinetic Concepts, Incorporated ofSan Antonio, Tex.; a bioresorbable material. The treatment manifold 112may still further include a scaffold material. In some situations, thetreatment manifold 112 may also be used to distribute fluids such asmedications, antibacterials, growth factors, and various solutions tothe tissue site 102. Other layers may be included in or on the treatmentmanifold 112, such as absorptive materials, wicking materials,hydrophobic materials, and hydrophilic materials.

In one illustrative, non-limiting embodiment, the treatment manifold 112may be constructed from a bioresorbable material that may remain in apatient's body following use of the reduced-pressure dressing. Suitablebioresorbable materials may include, without limitation, a polymericblend of polylactic acid (PLA) and polyglycolic acid (PGA). Thepolymeric blend may also include without limitation polycarbonates,polyfumarates, and capralactones. The treatment manifold 112 may furtherserve as a scaffold for new cell-growth, or a scaffold material may beused in conjunction with the treatment manifold 112 to promotecell-growth. A scaffold is a substance or structure used to enhance orpromote the growth of cells or formation of tissue, such as athree-dimensional porous structure that provides a template for cellgrowth. Illustrative examples of scaffold materials include calciumphosphate, collagen, PLA/PGA, coral hydroxy apatites, carbonates, orprocessed allograft materials.

The flexible film drape 114 may be sized so that the flexible film drape114 overlaps the wound 106 in such a manner that a portion of theflexible film drape 114 extends beyond the periphery of the wound 106 toform an extension 124. The flexible film drape 114 may be formed fromany material that provides a fluid seal. The flexible film drape 114may, for example, be an impermeable or semi-permeable, elastomericmaterial. Elastomeric material generally refers to a polymeric materialthat has rubber-like properties. More specifically, most elastomers haveultimate elongations greater than 100% and a significant amount ofresilience. The resilience of a material refers to the material'sability to recover from an elastic deformation. Examples of elastomersmay include, but are not limited to, natural rubbers, polyisoprene,styrene butadiene rubber, chloroprene rubber, polybutadiene, nitrilerubber, butyl rubber, ethylene propylene rubber, ethylene propylenediene monomer, chlorosulfonated polyethylene, polysulfide rubber,polyurethane (PU), EVA film, co-polyester, and silicones. Additional,specific examples of sealing member materials include a silicone drape,a 3M Tegaderm® drape, or a polyurethane (PU) drape such as one availablefrom Avery Dennison Corporation of Pasadena, Calif. Other devices may beused in lieu of the flexible film drape 114 to form a fluid seal overthe tissue site 102.

The attachment device 122 may be used to attach or help attach theflexible film drape 114 to the epidermis 107 or another layer, such as agasket or additional sealing member. The attachment device 122 may takenumerous forms. For example, the attachment device 122 may be amedically-acceptable, pressure-sensitive adhesive that is applied to theextension 124 of the flexible film drape 114. Alternatively, thepressure-sensitive adhesive may span the entire width of the flexiblefilm drape 114. Alternative attachment devices 122 may include, but arenot limited to, heat-activated adhesives, sealing tapes, double-sidedsealing tapes, pastes, hydrocolloids, hydrogels, hooks, sutures, orother devices. In addition, the composition 103 also forms a fluid sealproximate the tissue site 102 and between the epidermis 107 and at leasta portion of the flexible film drape 114. The composition 103 mayaugment or increase the strength of the seal provided by the attachmentdevice 122 alone.

The composition 103 may address leaks or hair management in theperiwound area. In some embodiments, the composition 103 may addressboth leaks and hair management in the periwound area. The composition103 may be disposed at least proximate the peripheral edge 113 of thetreatment manifold 112 and adjacent at least a portion of the epidermis107. For example, the composition 103 may be disposed to touch theperipheral edge 113, or within a few centimeters of the peripheral edge113. The composition 103 has a unified member or a portion that is softin that it can flow over or otherwise move into crevices andimperfections in the epidermis 107 or flow around hair protruding fromthe epidermis 107 to make a substantial fluid seal. The composition 103thereby forms a substantial fluid seal against the epidermis 107.

In addition, the composition 103 may be configured to modify the hair105 on the epidermis 107 as the hair 105 encounters the composition 103.In this regard, the composition 103 may include a hair-modificationagent to at least weaken the hair 105, i.e., inhibiting hair growth ordissolving the hair 105. Thus, the hair-modification agent may be a hairremoval agent or a hair-growth inhibiting agent. The hair removal agentmay be any active agent that removes hair. Some hair removal agents mayrequire a barrier layer to protect the skin from irritation.

The hair removal agent may be a depilatory composition or the like. Insome embodiments, the hair removal agent may be chemical depilatorycompositions that typically cleave disulfide bonds in hair keratin,causing the hair fiber to disintegrate. Non-limiting examples of a hairremoval agent include one or more of the following active agents:sulfhydryl compounds, thioglycolic acid and thioglycolate salts (forexample calcium thioglycolate). Compounds which help to maintain a highpH (such as calcium hydroxide) will assist in the breakdown of the hairand can form advantageous complexes with thioglycolic acid sulfhydrylcompounds. Sulfhydryl compounds include compounds having an —S—H groupselected from the group consisting of thioglycolic acid, cysteine,homocysteine, glutathione, thioglycerol, thiomalic acid,2-mercaptopropionic acid, 3-mercaptopropionic acid, thiodiglycol,2-mercaptoethanol, dithiothreitol, thioxanthene, thiosalicylic acid,thiolactic acid, thiopropionic acid, thiodiglycolic acid,N-acetyl-L-cysteine, lipoic acid, and cosmetically- orpharmaceutically-acceptable salts of any of the foregoing compounds.Mixtures of sulfhydryl compounds are suitable for use herein. Preferredsulfhydryl compounds include thioglycolic acid, cysteine, glutathione,N-acetyl-L-cysteine, lipoic acid, thiosalicylic acid, and thiolacticacid and cosmetically- and/or pharmaceutically-acceptable salts thereof.More preferred sulfhydryl compounds include thioglycolic acid, cysteine,glutathione and N-acetyl-L-cysteine and cosmetically- and/orpharmaceutically-acceptable salts thereof. The most preferred sulfhydrylcompound is N-acetyl-L-cysteine and cosmetically- orpharmaceutically-acceptable salts thereof.

Non-limiting examples of a hair-growth inhibiting agent include one ormore of the following: 5-alpha reductase, ornithine decarboxylase,S-adenosylmethionine decarboxylase, gamma-glutamyl transpeptidase,transglutaminase, or wortmannin. Wortmannin(11-(acetyloxy)-1,6b,7,8,9a,10,11,11b-octahydro-1-(methoxymethyl)-9a,11b-di-methyl-[1S-(1.alpha.,6b.alpha., 9a.beta., 11.alpha.,11b.beta.)]-3H-furo[4,3,2-de]indeno[4,5-h]-2-benzopyran-3,6,9-trione) isa fungal metabolite capable of entering intact cells and can induce celldeath by apoptosis.

The reduced-pressure subsystem 120 includes a reduced-pressure source126, which can take many different forms. The reduced-pressure source126 provides reduced pressure. The reduced-pressure source 126 may beany device for supplying a reduced pressure, such as a vacuum pump, wallsuction, micro-pump, or other source. In one embodiment, thereduced-pressure source may be a micro-pump associated with the flexiblefilm drape 114. While the amount and nature of reduced pressure appliedto the tissue site 102 will typically vary according to the application,the reduced pressure will typically be between −5 mm Hg and −500 mm Hgand more typically between −75 mm Hg and −300 mm Hg, and more typicallystill between −75 and −175 mm Hg. For example, and not by way oflimitation, the pressure may be −75, −80, −90, −100, −110, −120, −130,−140, −150, −160, −170, −175 mm Hg or another pressure.

Reduced pressure generally refers to a pressure less than the ambientpressure at a tissue site that is being subjected to treatment. In mostcases, this reduced pressure will be less than the atmospheric pressureat which the patient is located. Alternatively, the reduced pressure maybe less than a hydrostatic pressure at the tissue site. Unless otherwiseindicated, quantitative values of pressure stated herein are gaugepressures. The reduced pressure delivered may be constant or varied(patterned or random) and may be delivered continuously orintermittently. Although the terms “vacuum” and “negative pressure” maybe used to describe the pressure applied to the tissue site, the actualpressure applied to the tissue site may be more than the pressurenormally associated with a complete vacuum. Consistent with the useherein, unless otherwise indicated, an increase in reduced pressure orvacuum pressure typically refers to a reduction in absolute pressure.

In the illustrative embodiment of FIG. 1, the reduced pressure developedby the reduced-pressure source 126 is delivered through thereduced-pressure conduit 128, through canister 130, to areduced-pressure interface 132. In one illustrative embodiment, thereduced-pressure interface 132 is a TRAC® technology port available fromKinetic Concepts, Inc. of San Antonio, Tex. The reduced-pressureinterface 132 allows the reduced pressure to be realized within a sealedspace 134 below the flexible film drape 114 and realized within thetreatment manifold 112. The reduced-pressure interface 132 may also be atube placed directly through the flexible film drape into the treatmentmanifold.

In operation according to one illustrative embodiment, the treatmentmanifold 112 is disposed proximate the tissue site 102, e.g., the wound106. The composition 103 is at least disposed proximate the peripheraledge 113 of the treatment manifold 112 (and may go over the treatmentmanifold 112 as well in some embodiments). If the composition 103 has arelease liner on a patient-facing side (see 164 in FIG. 7), the releaseliner is first removed. The tissue site 102, the treatment manifold 112,and a portion of the epidermis 107 can be covered by the flexible filmdrape 114 to form the sealed space 134. The flexible film drape 114 andthe epidermis 107 are fluidly sealed at least in part by the composition103. The sealed space 134 contains the treatment manifold 112. If notalready coupled, the reduced-pressure interface 132 may be fluidlycoupled to the sealed space 134. The reduced-pressure interface 132 maybe fluidly coupled to the reduced-pressure source 126. Thereduced-pressure source may be activated, and reduced pressure can bedelivered to the sealed space 134.

As treatment progresses, hair encountering the composition 103 ismodified to grow slower, to dissolve, or to otherwise be weakened. Theweakened hair means the hair is relatively weaker than un-treated hairand may not tent the flexible film drape 114 or puncture the flexiblefilm drape 114. In addition, if not already dissolved, weakened hair mayreadily break when the dressing is removed thereby minimizing pain tothe patient.

Referring now primarily to FIG. 2, a cross-section is shown thatillustrates the hair 105 encountering the composition 103. The hair 105is extending into the composition 103 in this illustration. Thehair-modification agent in composition 103 may act on the hair 105 to atleast weaken the hair 105 as previously described. In addition, thiscross section shows the composition 103 has portions that flow intoimperfections 136, e.g., a crevice, in the epidermis 107 to form asubstantial fluid seal.

As previously mentioned, numerous embodiments and features of thecomposition 103 are possible, but the use may substantially be the same.Additional embodiments and features are now presented. Referring nowprimarily to FIG. 3, a portion of an illustrative embodiment of a systemfor treating a tissue site 102 of the patient 104, which has hair 105proximate the tissue site 102, with reduced pressure is presented. Thesystem 100 is analogous in most respects to the system 100 of FIG. 1,and accordingly, some parts are labeled but not further described here.In addition, components referenced but not explicitly shown areanalogous to those previously presented.

The system 100 includes a composition 103 that, in this illustrativeembodiment, may be formed as an annular gel member 138. The annular gelmember 138 may be shaped as a partial wedge member, as shown, or anothershape, e.g., a rectangular disc. A partial wedge member may have atriangular cross-sectional profile. In some embodiments, the annular gelmember 138 may have a peripheral portion that has a thickness less thana thickness of interior portions. The annular gel member 138 may be ablend of sealing and hair removal agents or may be formed as separatelayers.

Referring now primarily to FIG. 4, a cross-section of anotherillustrative embodiment of the composition 103 is presented. Thecomposition 103 is analogous in most respects to the compositions 103 ofFIGS. 1-3, and accordingly, some parts are labeled but not furtherdescribed here. In addition, components referenced but not explicitlyshown are analogous to those previously presented. In this exampleembodiment, the composition 103 is a hair-modification layer 140disposed adjacent a barrier layer 146 and a sealing layer 152.

The hair-modification layer 140 of FIG. 4 has a first side 142 and asecond side 144. The barrier layer 146 has a first side 148 and a secondside 150, and the sealing layer 152 has a first side 154 and a secondside 156. The barrier layer 146 substantially prevents or impedes thehair-modification layer 140 from migrating to the patient's epidermis.Thus, the barrier layer 146 may reduce the potential for skin irritationand allow for a more concentrated hair-modification agent to be used. Inaddition, the barrier layer 146 may minimize any unwanted interactionsbetween the sealing layer, e.g., adhesive, and the hair-modificationagent.

The second side 150 of the barrier layer 146 is disposed proximate thefirst side 154 of the sealing layer 152. The second side 144 of thehair-modification layer 140 is disposed proximate the first side 148 ofthe barrier layer 146. The second side 156 of the sealing layer 152 maybe covered with a release liner (not shown but analogous to releaseliner 164 in FIG. 7) prior to use.

The hair-modification layer 140 may be formed from a continuous phasemember from a polymer matrix such as a soft acrylic, silicone,polyurethane, hydrogel or hydrocolloid into which a hair-modificationagent has been dispersed or dissolved. The barrier layer 146 may beformed from polyolefin (gels, thermoplastic films, or elastomericfilms), silicone, or polyurethane films. The sealing layer may be a softacrylic, silicone, polyurethane, hydrogel, hydrocolloid, or polyolefingels.

FIG. 5 is a sectional view illustrating additional details of acomposition 203. The composition 203 may be similar to the composition103 described above with respect to FIGS. 1-4. Similar elements may havesimilar reference numbers that are indexed to 200. As shown in FIG. 5,the composition 203 may also be formed with only two layers: thehair-modification layer 240 adjacent the sealing layer 252. In thisillustrative embodiment, the second side 244 of the hair-modificationlayer 240 is disposed proximate the first side 254 of the sealing layer252.

Referring now primarily to FIG. 6, another illustrative embodiment of aportion of a system for treating a tissue site, which has hair proximatethe tissue site, with reduced pressure is presented. A composition 303is shown that may be analogous in most respects to the composition 103and the composition 203 of FIGS. 1-5, and accordingly, some parts arelabeled but not further described here. Similar elements may havesimilar reference numbers that are indexed to 300. In this illustrativeembodiment, a composition 303 and a flexible film drape 314 arecombined. The flexible film drape 314 has a first side 316 and a secondside 318. The composition 303 may include a layer 358 having sealing andhair modification properties, a first side 360, and a second side 362.The first side 360 of the layer 358 may be adjacent and coupled to thesecond side 318 of the flexible film drape 314. The layer 358 and theflexible film drape 314 are substantially co-extensive. In other words,the layer 358 substantially covers the second side 318 of the flexiblefilm drape 314. The layer 358 includes a sealing agent or material and ahair-modification agent.

Referring now primarily to FIG. 7, another illustrative embodiment of aportion of a system for treating a tissue site, which has hair proximatethe tissue site, with reduced pressure is presented. A composition 403is shown that may be analogous in most respects to the composition 103,the composition 203, and the composition 303 of FIGS. 1-6, andaccordingly, some parts are labeled but not further described here.Similar elements may have similar reference numbers that are indexed to400. Like in FIG. 6, a composition 403 and a flexible film drape 414 arecombined.

The composition 403 includes a hair-modification layer 440 having afirst side 442 and a second side 444 and a barrier layer 446 having afirst side 448 and a second side 450. The composition 403 may furtherinclude a sealing layer 452 having a first side 454 and a second side456. The first side 448 of the barrier layer 446 may be proximate thesecond side 444 of the hair-modification layer 440. The first side 454of the sealing layer 452 may be disposed proximate the second side ofthe hair-modification layer 440. The second side 456 of the sealinglayer 452 may be covered by a release liner 464. The release liner 464may be one or more of the following: a polyurethane film, high densitypolyethylene, polypropylene, a high-MVTR film, polymers such as acryliccopolymers, polyvinyl acetate, polyether block amide copolymers (PEBAX),polyvinyl alcohol and copolymers, polyamide, polyvinylchloride, castingpaper, or polyvinylidene chloride.

The first side 442 of the hair-modification layer 440 is disposedproximate the second side 418 of the flexible film drape 414. Theflexible film drape 414, the hair-modification layer 440, the barrierlayer 446, and sealing layer 452 may be coupled, for instance, bymechanical interlocking, e.g., the barrier layer 446 may be a film andthe layers 440, 452 may be soft and gel-like, and/or thermodynamicadhesion, e.g., the layers may be co-extruded or formed by multiplecasting the hair-modification layer 440, the barrier layer 446, and thesealing layer 452 onto each other.

Referring now primarily to FIG. 8, another illustrative embodiment of acomposition 503 is presented. The composition 503 of FIG. 8 is analogousin most respects to the composition 203 of FIG. 5, except an odor layer866 has been added. Similar elements may have similar reference numbersindexed to 800. The odor layer 866 may be a separate layer or mayintegrated into another layer or layers. The odor layer 866 may beformed from a material that inhibits or reduces odor. For example, theodor layer 866 may be formed from an activated carbon or clay.

Referring now primarily to FIG. 9, another illustrative embodiment of aportion of a system for treating a tissue site, which has hair proximatethe tissue site, with reduced pressure is presented. A composition 603is illustrated. The composition 603 of FIG. 9 may be similar to andinclude elements similar to the composition 103, the composition 203,the composition 303, the composition 403, and the composition 503 ofFIGS. 1-8. The similar elements may have similar numbers indexed to 600.The composition 603 may be formed with a fabric layer 668. The fabriclayer 668 may be woven or non-woven and is impregnated with ahair-modification agent, i.e., a hair removal agent or hair-growthinhibiting agent. Impregnation of the fabric layer 668 may involveforcing a liquid substance into porous spaces of the fabric layer 668.Impregnation may combine the hair modification properties of thehair-modification agent with the properties of the fabric layer 668.

The fabric layer 668 has a first side 670 and second side 672. Thecomposition 603 also includes a sealing layer 652 having a first side654 and a second side 656. The first side 654 of the sealing layer 652is disposed proximate the second side 672 of the fabric layer 668. Thefirst side 670 of the fabric layer 668 is disposed proximate and coupledto the second side 618 of the flexible film drape 614. Alternatively,the fabric layer 668 may be laminated onto the flexible film drape 614.Alternatively, the flexible film drape 614 may be cast, for example,from melt, solution, or dispersion, onto the fabric layer 668. Thisillustrative embodiment may provide additional stiffness to the flexiblefilm drape 614.

Referring now primarily to FIG. 10, a cross section of anotherillustrative embodiment of a composition 703 is presented. Thecomposition 703 is analogous in most respects to the composition 103,the composition 203, the composition 303, the composition 403, thecomposition 503, and the composition 603 of FIGS. 1-9, and accordingly,some parts are labeled but not further described here. Similar elementsmay be referenced by similar numbers indexed to 700. In addition,components referenced but not explicitly shown are analogous to thosepreviously presented. The composition 703 differs from the embodiment ofFIG. 4 in that an insulating layer 774 has been added. The insulatinglayer 774 may limit heat transfer from the patient through the areasthat may be covered by the insulating layer 774. By limiting heattransfer, the insulating layer 774 may help inhibit hair growth. Theinsulating layer 774 may be foam or any material providing for theretention of heat. While the insulating later 774 is shown on thehair-modification layer 740, the insulating layer 774 may be located atother locations in the composition 703, e.g., the insulating layer 774may be beneath (for orientation shown) the hair-removal layer 740 orbeneath the barrier layer 746. The insulating layer 774 may be orientedbeneath the hair-removal layer 740 and/or the barrier layer 746, inwhich case the insulating layer 774 may be formed of a soft gel therebypermitting hair to penetrate the insulating layer 774, which may beeither a foam or contain bubbles or spheres, such as the filler soldunder the trademark EXPANCEL, to increase heat insulation properties ofthe insulating layer 774. Alternatively, the insulating layer 774 may beoriented above the hair-removal layer 740 and/or the barrier layer 746,in which case the insulating layer 774 may be formed from a film, foamedor containing bubbles or spheres, or filled with insulating fillers,such as talc or silica.

Referring now primarily to FIGS. 11-12B, another illustrative embodimentof a portion of a system for treating a tissue site, which has hairproximate the tissue site, with reduced pressure is presented. Thesystem includes a composition 803 that includes hair-modification agent875 encapsulated within an activatable shell 876. The composition 803 isanalogous in most respects to the composition 103, the composition 203,the composition 303, the composition 403, the composition 503, thecomposition 603, and the composition 703 of FIGS. 1-10, and accordingly,some parts are labeled but not further described here. Similar elementsmay be referenced by similar numbers indexed to 800. In addition,components referenced but not explicitly shown are analogous to thosepreviously presented. The activatable shell 876 has an un-activatedstate shown in FIG. 12A and an activated state shown in FIG. 12B. Thehair-modification agent 875 may be any of the types referenced elsewhereherein. The hair-modification agent 875 may be within a singleactivatable shell 876 or more typically a plurality of activatableshells 876 or as shown in FIG. 11.

The activatable shell 876 may be configured to isolate thehair-modification agent 875 from the surroundings 880 when in theun-activated state (FIG. 12A). When the activatable shell 876 is in theactivated state (FIG. 12B), the hair-modification agent 875 is notisolated from the surrounding 880, i.e., the hair-modification agent 875may be in fluid communication with the surroundings 880. As shown inFIG. 12B, an activation device 882 may be used to activate theactivatable shell 876 to change the activatable shell 876 from theun-activated state to the activated state.

In one illustrative embodiment, the activatable shell 876 may be formedfrom a phototriggerable microcapsule made of a polyamide. In thisembodiment, the hair-modification agent 875 includes carbon nano tubes(CNT). The hair-modification agent is co-encapsulated with carbonnanotubes using interfacial polymerization. The incorporation of carbonnanotubes endows the activatable shells with the ability to response toan external optical event. The triggered or activated release of liquidfrom the activatable shell may be achieved with irradiation with anear-IR laser. Thus, the activation device 882 is a light gun that heatsthe CNT causing expansion that ruptures the activatable shell, therebyexposing the hair-modification agent 875. Other activatable shell typesmay be used with a corresponding variety of activation devices (e.g.,heat, light, etc.). It should be apparent, that the embodiment of FIGS.11-12B allows a user to choose when to activate the hair-modificationagent 875.

It should be clear that the systems, devices, and methods describedherein may be used with humans or with other animals. In this regard, itshould be noted that the chemical composition of human hair and animalfur is the same (Keratin).

It should also be apparent that the systems, methods, and devices hereinmay provide numerous benefits. For example, hair growth can be managedthrough the treatment. Leaks—even low flow leaks—may be minimized oreliminated. A thin flexible film drape, e.g., 15 μm-60 μm, may be usedwhich should relatively enhance the moisture-vapor-transmission rate. Athinner drape should allow for more comfort. Removal of the system orcomponents described herein should be relatively less painful because ofthe absence of hair or at least weakened hair under the dressing.

The hair-modification agent and sealing agent may be associated in anyof the ways shown above. The hair-modification agent and sealing agentmay be in layers near each other or may be mixed or some combination.

Although the present invention and its advantages have been disclosed inthe context of certain illustrative, non-limiting embodiments, it shouldbe understood that various changes, substitutions, permutations, andalterations can be made without departing from the scope of theinvention as defined by the appended claims. It will be appreciated thatany feature that is described in connection to any one embodiment mayalso be applicable to any other embodiment. For example, the releaseliner shown in FIG. 7, may be applied to any of the embodiments shown.As another example, the odor layer 566 of FIG. 8 may be added to any ofthe embodiments.

It will be understood that the benefits and advantages described abovemay relate to one embodiment or may relate to several embodiments. Itwill further be understood that reference to “an” item refers to one ormore of those items.

The steps of the methods described herein may be carried out in anysuitable order, or simultaneously where appropriate.

Where appropriate, aspects of any of the embodiments described above maybe combined with aspects of any of the other embodiments described toform further examples having comparable or different properties andaddressing the same or different problems.

It will be understood that the above description of preferredembodiments is given by way of example only and that variousmodifications may be made by those skilled in the art. The abovespecification, examples and data provide a complete description of thestructure and use of exemplary embodiments of the invention. Althoughvarious embodiments of the invention have been described above with acertain degree of particularity, or with reference to one or moreindividual embodiments, those skilled in the art could make numerousalterations to the disclosed embodiments without departing from thescope of the claims.

We claim:
 1. A system for treating a tissue site, the system comprising:a pad having a peripheral edge; a drape adapted to cover the pad to forma sealed space containing the pad; a hair-modification agent adapted tobe disposed adjacent the peripheral edge of the pad between the drapeand an epidermis to modify hair on the epidermis adjacent the tissuesite; a barrier layer disposed adjacent to a side of thehair-modification agent; and a sealing layer disposed adjacent to a sideof the barrier layer opposite the hair-modification agent, the sealinglayer adapted to contact the epidermis.
 2. The system of claim 1,wherein the hair-modification agent is dispersed in a continuous phasemember with an adhesive.
 3. The system of claim 1, wherein thehair-modification agent is selected from the group consisting of:thioglycolic acid, thioglycolate salts, calcium hydroxide, andsulfhydryl compounds.
 4. The system of claim 1, wherein thehair-modification agent comprises a hair removal agent.
 5. The system ofclaim 1, wherein the hair-modification agent comprises a hair-growthinhibiting agent.
 6. The system of claim 5, wherein the hair-growthinhibiting agent comprises wortmannin.
 7. The system of claim 1, whereinthe hair-modification agent is dispersed in a gel member.
 8. The systemof claim 1, wherein the drape has a first side and a second side, andwherein the hair-modification agent covers the second side of the drape.9. The system of claim 1, further comprising a release liner disposedproximate a side of the sealing layer opposite the barrier layer. 10.The system of claim 1, further comprising an insulating layer.
 11. Thesystem of claim 1, wherein the hair-modification agent is disposed in ahair-modification layer, and the system further comprises a sealinglayer configured to be disposed between the hair-modification layer andthe epidermis.
 12. The system of claim 1, wherein the hair-modificationagent is disposed in a hair-modification layer and the system furthercomprises a barrier layer configured to be disposed between thehair-modification layer and the epidermis.
 13. The system of claim 1,wherein the hair-modification agent is disposed in a hair-modificationlayer, and the system further comprises a sealing layer disposedproximate a side of the hair-modification layer.
 14. The system of claim1, wherein the hair-modification agent is dispersed in a polymer matrix.15. The system of claim 14, wherein the polymer matrix comprises atleast one of the following: an acrylic, a silicone, a polyurethane, ahydrogel, and a hydrocolloid.
 16. The system of claim 1, wherein thehair-modification agent is dissolved within a polymer matrix.
 17. Thesystem of claim 1, wherein the system further comprises an odor layer.18. The system of claim 17, wherein the odor layer comprises activatedcarbon.
 19. The system of claim 17, wherein the odor layer comprisesclay.
 20. The system of claim 1, wherein: the barrier layer is formedfrom a material selected from the group consisting of polyolefins,silicone, and polyurethane; and the sealing layer is selected from thegroup consisting of a soft acrylic, silicone, polyurethane, hydrogel,hydrocolloid, and polyolefin gels.
 21. The system of claim 1, wherein:the hair-modification agent is impregnated in a fabric layer; thesealing layer is disposed proximate a side of the fabric layer; and thedrape is disposed proximate a side of the fabric layer opposite thesealing layer.
 22. The system of claim 21, wherein the fabric layer is anon-woven material.
 23. The system of claim 21, wherein the fabric layeris a woven material.
 24. The system of claim 1, further comprising afabric layer laminated into the drape, wherein the hair-modificationagent is impregnated in the fabric layer.
 25. The system of claim 1,further comprising: a shell encapsulating the hair-modification agent,the shell having a un-activated state and an activated state, whereinthe shell fluidly isolates the hair-modification agent in theun-activated state, and the shell permits fluid communication with thehair-modification agent in the activated state; and an activating devicethat is configured to change the shell from the un-activated state tothe activated state.
 26. The system of claim 25, wherein the shellcomprises a polyamide shell and the activating device comprises a devicethat emits light.
 27. The system of claim 1, wherein the pad comprises aporous member having one or more flow channels.
 28. The system of claim1, wherein the pad comprises a manifold configured to distribute areduced pressure.
 29. A dressing for treating a tissue site, thedressing comprising: a gasket formed into an annulus, the gasketcomprising: a sealing layer having a uniform cross-sectional profile andcomprising a sealing agent disposed therein; a hair-modification layerhaving a partial wedge cross-sectional profile and comprising ahair-modification agent configured to modify hair on epidermis adjacentthe tissue site disposed therein, the hair-modification layer associatedwith the sealing layer; and a barrier layer deposed between the sealinglayer and the hair-modification layer.
 30. The dressing of claim 29,wherein the hair-modification layer further comprises a continuous phasemember.
 31. The dressing of claim 29, wherein the gasket comprises a gelmember.
 32. The dressing of claim 29, wherein the hair-modificationagent comprises a hair removal agent.
 33. The dressing of claim 32,wherein the hair removal agent comprises at least one of the following:thioglycolic acid, thioglycolate salts, calcium hydroxide, andsulfhydryl compounds.
 34. The dressing of claim 29, wherein thehair-modification agent comprises a hair-growth inhibiting agent. 35.The dressing of claim 34, wherein the hair-growth inhibiting agentcomprises wortmannin.
 36. The dressing of claim 29, wherein thehair-modification layer further comprises a polymer matrix.
 37. Thedressing of claim 29, wherein the hair-modification agent isencapsulated within a shell having an un-activated state and anactivated state, in the un-activated state the shell fluidly isolatesthe hair-modification agent and in the activated state the shell permitsfluid communication with the hair-modification agent.
 38. The dressingof claim 29, further comprising an insulating layer.
 39. A dressing fortreating a tissue site, the dressing comprising: a treatment pad havinga peripheral edge; a drape adapted to cover the treatment pad to form asealed space containing the treatment pad; a hair-modification layerhaving a hair-modification agent disposed therein, the hair-modificationlayer adapted to be disposed at least adjacent the peripheral edge ofthe treatment pad between the drape and epidermis adjacent the tissuesite; a barrier layer disposed adjacent to a side of thehair-modification layer; and a sealing layer disposed adjacent to a sideof the barrier layer opposite the hair-modification layer, the sealinglayer adapted to contact the epidermis.
 40. The dressing of claim 39,wherein the hair-modification layer is coupled to the drape.
 41. Thedressing of claim 39, wherein the treatment pad is a manifold.
 42. Amethod for treating a tissue site, the method comprising: disposing amanifold having a peripheral edge adjacent the tissue site; disposing agasket formed into an annulus, the gasket comprising: a sealing layerhaving a uniform cross-sectional profile and comprising a sealing agentdisposed therein; a hair-modification layer having a partial wedgecross-sectional profile and comprising a hair-modification agentdisposed therein, the hair-modification layer adjacent the peripheraledge of the manifold and adjacent at least a portion of an epidermis;and a barrier layer deposed between the sealing layer having the sealingagent disposed therein and the hair-modification layer having thehair-modification agent disposed therein; and disposing a drape over themanifold and the gasket to form a sealed space containing the manifold.